A liquid crystal lens (LC lens) is created based on unique physical and optical features of liquid crystal material. Unlike conventional glass lens, an LC lens may converge or diverge light passing therethough in response to an electric field applied thereto. When indium tin oxide (ITO) electrodes contained therein are configured as strips, the lens may function like a lenticular lens. By properly disposing the lens above an LC panel, the image of right-eye pixels can be refracted and reach the right eye of a user, and the image of left-eye pixels can be refracted and reach the left eye of the user. Therefore, stereo perception can be acquired with no need of glasses.
Please refer to FIG. 1. In a common LC display device, light is emitted out of an LC panel 1 through an LC lens 2. When an LCD device is in an off state, light passes through the LC panel 1 and the LC lens 2 directly without change in the advancing direction. On the other hand, when the LC display device is in an on state, there will be a slant angle θ existing between the advancing direction of light through the LC panel 1 and that through the LC lens 2 as the ITO electrodes 3 in the LC lens 2 have the deflective slant angle θ from a central axis extending along width of the LC lens.
As shown in FIG. 2, the LCD device includes an LC panel 1, an LC lens 2 and a slant polarization sheet 4 disposed between the LC panel 1 and the LC lens 2. The LC lens 2 is composed of an upper glad substrate 21, a first electrode layer 22, an LC layer 23, a thin film layer 24, a second electrode layer 25 and a lower glass substrate 26. After light is emitted out of the LC panel 1, deflection of light occurs due to the slant angle θ existing between the LC panel 1 and the LC lens 2. Therefore, it is necessary to dispose the slant polarization sheet 4 between the LC panel 1 and the LC lens 2 to rotate the emitted light by an angle of 90-θ so as to assure of the linearity of the light.
The LCD device has the following drawbacks. For display manufacturers, disposing the slant polarization sheet 4 between the LC panel 1 and the LC lens 2 requires additional cost. Moreover, due to the existence of the slant polarization sheet 4 between the LC panel 1 and the LC lens 2, an interface scattering effect would become significant and light concentration effect would be deteriorated.